Display Device and Method of Manufacturing the Same

This application claims priority to and benefits of Korean Patent Application No. 10-2024-0061324 under 35 U.S.C. § 119, filed on May 9, 2024 in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

The disclosure relates to a display device and a method of manufacturing the same, and an electronic device for providing an image.

As society becomes more information-orientated, increasing demands are placed on display devices to display images in various ways. In line with this trend, various types of display devices, including light emitting display devices, are being developed. A light emitting display device may include a pixel that includes a light emitting element.

Aspects of the disclosure provide a display device that may enhance manufacturing efficiency and a method for manufacturing the same, and an electronic device for providing an image.

According to an aspect of the disclosure, a display device is provided, including a lower substrate, a bonding electrode disposed on the lower substrate, and a light emitting element disposed on the bonding electrode. The bonding electrode may include a first bonding metal layer and a second bonding metal layer sequentially disposed on the lower substrate, each including a bonding metal, a third bonding metal layer disposed between the first bonding metal layer and the second bonding metal layer, also including the bonding metal, a first thin film layer disposed between the first bonding metal layer and the third bonding metal layer, and a second thin film layer disposed between the second bonding metal layer and the third bonding metal layer. The first thin film layer and the second thin film layer may include a material with an atomic volume that is greater than or equal to about 80% of an atomic volume of the bonding metal.

In an embodiment, the first bonding metal layer, the second bonding metal layer, and the third bonding metal layer may include at least one of titanium (Ti), zirconium (Zr), nickel (Ni), or chromium (Cr).

In an embodiment, the first thin film layer and the second thin film layer may include at least one of gold (Au), zirconium (Zr), silver (Ag), hafnium (Hf), palladium (Pd), or platinum (Pt).

In an embodiment, the first bonding metal layer, the second bonding metal layer, and the third bonding metal layer may include titanium (Ti), and the first thin film layer and the second thin film layer may include at least one of gold (Au), or zirconium (Zr).

In an embodiment, each of the first bonding metal layer and the second bonding metal layer may have a thickness in a range of about 100 nm to about 300 nm.

In an embodiment, a thickness of the third bonding metal layer may be less than or equal to the thickness of each of the first bonding metal layer and the second bonding metal layer.

In an embodiment, each of the first thin film layer and the second thin film layer may have a thickness in a range of about 1 nm to about 50 nm.

In an embodiment, the bonding electrode may further include a bonding layer disposed between the lower substrate and the first bonding metal layer.

In an embodiment, the bonding electrode may further include a reflective layer disposed between the second bonding metal layer and the light emitting element.

In an embodiment, the lower substrate may further include a semiconductor substrate including a pixel circuit, a connection electrode that connects the pixel circuit to the bonding electrode, and a first insulating layer disposed on the semiconductor substrate and surrounding the connection electrode.

In an embodiment, the light emitting element may include a first semiconductor layer, a light emitting layer, and a second semiconductor layer, which are sequentially disposed on the bonding electrode.

In an embodiment, the display device may further include a second insulating layer surrounding a side surface of the light emitting element, and a common electrode disposed on the light emitting element.

In an embodiment, the display device may further include a reflection film surrounding the side surface of the light emitting element.

According to an aspect of the disclosure, a method of manufacturing a display device is provided, including, preparing a first substrate including a semiconductor circuit substrate, with a first bonding metal layer and a first thin film layer sequentially disposed on the semiconductor circuit substrate, preparing a second substrate including a semiconductor substrate, with an epi-layer, a second bonding metal layer, and a second thin film layer sequentially disposed on the semiconductor substrate, disposing the second substrate on the first substrate such that the first thin film layer and the second thin film layer face each other, and bonding the first substrate to the second substrate, separating the semiconductor substrate from the epi-layer, and forming a bonding electrode and a light emitting element by etching a lower bonding layer including the first bonding metal layer and the first thin film layer, the epi-layer, and an upper bonding layer including the second bonding metal layer and the second thin film layer. The first bonding metal layer and the second bonding metal layer may include a bonding metal, and the first thin film layer and the second thin film layer may include a material with an atomic volume that is greater than or equal to about 80% of an atomic volume of the bonding metal.

In an embodiment, the first bonding metal layer and the second bonding metal layer may include at least one of titanium (Ti), zirconium (Zr), nickel (Ni), or chromium (Cr).

In an embodiment, the first thin film layer and the second thin film layer may include at least one of gold (Au), zirconium (Zr), silver (Ag), hafnium (Hf), palladium (Pd), or platinum (Pt).

In an embodiment, the first bonding metal layer and the second bonding metal layer may include titanium (Ti), and the first thin film layer and the second thin film layer may include at least one of gold (Au), or zirconium (Zr).

In an embodiment, the bonding of the first substrate to the second substrate may include forming a third bonding metal layer including the bonding metal between the first thin film layer and the second thin film layer.

In an embodiment, each of the first bonding metal layer and the second bonding metal layer may have a thickness in a range of about 100 nm to about 300 nm.

In an embodiment, each of the first thin film layer and the second thin film layer may have a thickness in a range of about 1 nm to about 50 nm.

According to an aspect of the disclosure, an electronic device for providing an image is provided, including a display device. The display device may include a lower substrate, a bonding electrode disposed on the lower substrate, and a light emitting element disposed on the bonding electrode. The bonding electrode may include a first bonding metal layer and a second bonding metal layer sequentially disposed on the lower substrate, each including a bonding metal, a third bonding metal layer disposed between the first bonding metal layer and the second bonding metal layer, also including the bonding metal, a first thin film layer disposed between the first bonding metal layer and the third bonding metal layer, and a second thin film layer disposed between the second bonding metal layer and the third bonding metal layer. The first thin film layer and the second thin film layer may include a material with an atomic volume that is greater than or equal to about 80% of an atomic volume of the bonding metal.

According to the display device and the method of manufacturing the same, the diffusion of bonding metals may be promoted by forming thin film layers on bonding metal layers of a first substrate and a second substrate. Accordingly, the first substrate and the second substrate may be bonded smoothly without requiring a planarization process for the bonding metal layers. In embodiments, the manufacturing efficiency of the display device formed from the first substrate and the second substrate may be enhanced.

However, the effects according to the embodiments of the disclosure are not limited to those described above, and various other effects are also contemplated.

The disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments are shown. This disclosure may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Various embodiments do not have to be exclusive nor limit the disclosure. For example, specific shapes, configurations, and characteristics of an embodiment may be used or implement in another embodiment.

In the drawings, sizes, thicknesses, ratios, and dimensions of elements may be exaggerated for ease of description and for clarity. Like reference numbers and/or reference characters refer to like elements throughout.

As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It will be understood that, although the terms “first,” “second,” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the disclosure.

The term “about” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” may mean within one or more standard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

In the specification and the claims, the term “and/or” is intended to include any combination of the terms “and” and “or” for the purpose of its meaning and interpretation. For example, “A and/or B” may be understood to mean “A, B, or A and B.” The terms “and” and “or” may be used in the conjunctive or disjunctive sense and may be understood to be equivalent to “and/or.”

In the specification and the claims, the phrase “at least one of A and B” may be construed as A only, B only, or any combination of A and B. Also, “at least one of X, Y, and Z” and “at least one selected from the group consisting of X, Y, and Z” may be construed as X only, Y only, Z only, or any combination of two or more of X, Y, and Z.

The terms “comprises,” “comprising,” “includes,” and/or “including,” “has,” “have,” and/or “having,” and variations thereof when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The phrase “in a plan view” means viewing the object from the top, and the phrase “in a schematic cross-sectional view” means viewing a cross-section of which the object is vertically cut from the side. Hence, the expression “in a plan view” used herein may mean that an object is viewed in the third z direction from the top. The phrase “in a schematic cross-sectional view” means viewing a cross-section in the first x direction or the second y direction of which the object is vertically cut from the side. The third z direction also can be referred to as a “thickness direction.”

In a case that an element, such as a layer, a region, a portion, or the like, is referred to as being “on,” “connected to,” or “coupled to” another element or layer, it may be directly on, connected to, or coupled to the other element or layer or intervening elements or layers may be present. However, in a case that an element or layer is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element or layer, there are no intervening elements or layers present. To this end, the term “connected” may refer to physical and/or electrical connection, with or without intervening elements.

The spatially relative terms “below,” “beneath,” “lower,” “above,” “upper,” or the like, may be used herein for ease of description to describe the relations between one element or component and another element or component as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, in the case where a device illustrated in the drawing is turned over, the device positioned “below” or “beneath” another device may be placed “above” another device. Accordingly, the illustrative term “below” may include both the lower and upper positions. The device may also be oriented in other directions and thus the spatially relative terms may be interpreted differently depending on the orientations.

Unless otherwise defined or implied herein, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Features of various embodiments of the disclosure may be partially or entirely combined and may interwork in different technical ways. Each embodiment may be implemented independently or in combination with other embodiments.

is a schematic perspective view illustrating a display device according to an embodiment.is a schematic plan view showing an example of area Aof.

Referring to, a display deviceaccording to an embodiment may include a display panel DPN, which includes a display area DA and a non-display area NDA. In an embodiment, the display devicemay be included in or provided with an electronic device. For example, the display devicemay be included in or provided with one of various types of electronic devices for providing an image. Alternatively, the display devicemay be provided alone.

The display panel DPN may have a quadrilateral planar shape having long sides in a first direction DRand short sides in a second direction DR. In, the first direction DRmay refer to a horizontal direction (or vertical direction) of the display panel DPN, while the second direction DRmay refer to a vertical direction (or horizontal direction) of the display panel DPN. A third direction DRmay refer to a thickness direction or a height direction of the display panel DPN. However, the planar shape of the display panel DPN is not limited to a quadrilateral shape, and the display panel DPN may have a different shape. For example, the display panel DPN may include a polygonal shape, a circular shape, an elliptical shape, or an irregular shape in a plan view.

The display area DA may be where images are displayed, while the non-display area NDA may be where no images are displayed. In an embodiment, the planar shape of the display area DA may follow the planar shape of the display panel DPN.illustrates an embodiment in which the display area DA has a quadrilateral planar shape. The display area DA may be disposed in a central area of the display panel DPN, while the non-display area NDA may be disposed around the display area DA. For example, the non-display area NDA may surround the display area DA.

The display panel DPN may include multiple pixels PX arranged in the display area DA. For example, the display panel DPN may include first pixels PXemitting light of a first color, second pixels PXemitting light of a second color, and third pixels PXemitting light of a third color. In an embodiment, the first color may be red, the second color may be green, and the third color may be blue, but they are not limited to these colors. At least one first pixel PX, at least one second pixel PX, and at least one third pixel PXadjacent to each other may form each unit pixel UPX, capable of emitting light of various colors. For example, the first pixel PX, the second pixel PX, and the third pixel PX, disposed adjacent to each other in a K-th (K is a natural number) row of the display area DA, may form one unit pixel UPX. The number, type, and/or arrangement of the pixels PX forming the unit pixel UPX may vary depending on the embodiments.

Each pixel PX may include at least one light emitting element LE. For example, each pixel PX may include a single light emitting element LE or may include multiple light emitting elements LE.

The light emitting elements LE may have a circular shape, a quadrilateral shape, or another planar shape. For example, the shape of the light emitting elements LE may vary depending on the embodiments.

In an embodiment, the light emitting element LE may be a micro light emitting diode (micro LED) having a small size in the micrometer (μm) range. For example, each light emitting element LE may be a micro LED having a length (e.g., horizontal length) in the first direction DR, a length (e.g., vertical length) in the second direction DR, and a length (e.g., thickness or height) in the third direction DR, which each dimension is several to hundreds of micrometers. In an embodiment, the length of the light emitting element LE in the first direction DR, the second direction DR, and the third direction DRmay be approximately less than or equal to 100 μm, but is not limited to this dimension.

In an embodiment, the first pixels PX, the second pixels PX, and the third pixels PXmay include light emitting elements LE that emit light of the first color, light of the second color, and light of the third color, respectively. In another embodiment, the first pixels PX, the second pixels PX, and the third pixels PXmay include light emitting elements LE that emit light of the same color, and light conversion patterns (e.g., wavelength conversion patterns including quantum dots) and/or color filters may be disposed in the emission areas of the first pixels PX, the second pixels PX, and/or the third pixels PXto convert or control the color of light emitted from the light emitting elements LE provided in each pixel PX.

In an embodiment, the pixels PX may be arranged in the display area DA in a matrix form, a stripe form, or any other form. The sizes of the pixels PX (or the emission areas of the pixels PX) may be substantially the same or different from each other.